(1) Field of the Invention
The invention relates to a drill-elastic and flexurally rigid rod element for supporting and guiding a movable flap relatively to a wing of an aircraft.
(2) Description of Related Art
The general term “aircrafts” will hereinbelow refer to fixed wing aircrafts as well as to rotary wing aircrafts, that is, the term “wings” comprises an airfoil wing of the fixed wing aircraft as well as a rotor blade of the rotary wing aircraft. Even though the invention can on principal also be used for fixed wing aircrafts, only a rotor blade of a rotary wing aircraft will be considered below in detail.
It is known that air vortexes, which generate noise and vibrations, are created during rotor operation on rotor blades of a rotary wing aircraft. These air vortexes are noticeable in particular in a cabin of the rotary wing aircraft, they impact the passenger comfort and negatively impact the durability of essential components of the rotary wing aircraft. This, in turn, limits the range of use of the rotary wing aircraft. Rotor blades, which are equipped with movable rotor blade flaps, which can be controlled by means of actuators, are used to avoid such air vortexes.
A rotor blade with a movably supported flap is known from DE 101 16 479 A1. The flap is movably fastened to the rotor blade by means of ball bearings. The control of the flap is carried out via a piezo actuator, which is arranged at a distance in a front area of the rotor blade, viewed in the direction of the profile depth.
With known rotor blades of the afore-mentioned type, the efficiently of the flap already decreases after a relatively short period of operation and it rapidly loses its efficiency, because a play is rapidly created due to wear of the highly-stressed flap bearing. The available deflection area of the flap is thus reduced, the aerodynamic and mechanical flap effect decreases and the friction in the flap bearing is highly increased. This, in turn, also impacts the efficiency of the actuator, which controls the flap. Extensive maintenance or replacement operations are thus required within relatively brief time intervals.
A connecting means, which provides for a ball bearing-free support of a movable flap on a rotor blade of a rotary wing aircraft is known from DE 199 09 257 C1. For this, the connecting means is arranged in the area between rotor blade and flap and is connected to the rotor blade and the flap via corresponding connecting areas. A torsion of the connecting means takes place in response to a deflection of the flap. The generic connecting means is embodied as a drill-elastic and flexurally rigid rod element made of fiber composite material and can encompass a cross-shaped profile cross section.